The use of medical balloons for treatment in the vascular system or other lumens of the body is well known. In a common situation, a medical balloon in a compact uninflated configuration mounted on a catheter shaft is inserted into the body via an introducer and guided through the vascular system. When the balloon reaches the desired treatment site within a body lumen, a fluid is injected through an inflation lumen in the catheter shaft to inflate the balloon. The balloon expands in an outward (i.e., radial) direction as it inflates, thereby dilating the body lumen at the treatment site. The fluid may then be withdrawn from the balloon via the inflation lumen, causing the balloon to deflate so that it can be moved to the next treatment site or withdrawn.
When the medical balloon is made from a noncompliant material, the uninflated balloon is typically folded into a pleated configuration and then the pleats are tightly wrapped circumferentially around the balloon to provide a low profile, thereby easing insertion of the uninflated balloon through the introducer and movement through the vascular system. Once the balloon is inflated, however, the pleats typically disappear, especially if the balloon is inflated to a high pressure. Upon deflation, the balloon may collapse in a random manner, forming a different number of pleats than originally present in the uninflated balloon. These randomly created pleats may have a larger, or otherwise less desirable, profile than that of the uninflated balloon. A need therefore exists, for a medical balloon with enhanced refolding properties during deflation.